Programmer Guide/SPU Reference/SSIGIN

Read/write signal from/to a wave item.

[SPU SIGOUT SIG X1 .. X8 OUT SR I XMAX]

	description	frame position
RSIGIN	random read → read frame centered around position POS	POS-L/2 .. POS+L/2-1 0 ≤ POS < SIG[!length]
ASIGIN	absolute read → read frames (blocks) without overlap	I*L/2 .. POS+L/2-1 0 ≤ POS < SIG[!length]

input	description	data type	value type	default value
A	input data	number, vector	variable
B	masker or threshold	number, vector	variable
C	replacement data	number, vector	variable
COND	condition	number (int.), string	variable	0
output	description	data type	value type	comment
Y	masked data	same type as A	variable

Description

If the condition defined by COND is true, C_i is assigned to Y_i, otherwise Y_i is set to A_i.

If A is a vector, the inputs B and C can be numbers or vectors with the same length as A. The output Y has always the same type as A.

COND	Assignment
0 or <	Y i = { C [ i ] if  A i < B [ i ] A i otherwise {\displaystyle Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}<B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}} $Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}<B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}$
1 or >	Y i = { C [ i ] if  A i > B [ i ] A i otherwise {\displaystyle Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}>B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}} $Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}>B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}$
2 or ≤	Y i = { C [ i ] if  A i ⩽ B [ i ] A i otherwise {\displaystyle Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}\leqslant B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}} $Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}\leqslant B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}$
3 or ≥	Y i = { C [ i ] if  A i ⩾ B [ i ] A i otherwise {\displaystyle Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}\geqslant B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}} $Y_{i}={\begin{cases}C_{[i]}&{\mbox{if }}A_{i}\geqslant B_{[i]}\\A_{i}&{\mbox{otherwise}}\end{cases}}$

with: 0 ≤ i < length of A; [i] means: index is used only if the input is a vector

See also

<SP-atoms>

SSIGIN - read signal (for filters, ...)

Usage:

SSIGIN SIG REV L S K D

Inputs:

SIG	name of shell-wave-item	no default
REV	0, YES|1)	def.=NO
L	frame length in samples (>=4)	def.=1024
S	frame shift in samples (1 <= S <= L)	def.=L/4
K	amplification factor	def.=1
D	differentiation factor (0..1)	def.=0

Outputs:

Xi	signal of channel i (L samples)
SR	sampling rate in Hz
N	number of frames
I	frame counter (0..N)

Function:

This atom implements an alternative signal-frame read function that can be used instead of CSIGN. The frame-splitting method is designed to be used for filter or other frequency-domain processing methods. The partitioning of the signal is similar to the method used by the phase vocoder, but no windowing or other processing is applied to the frames. The picture below shows the frame partitioning method:

Frame partitioning method used by SSIGIN

Notes:

This read function is currently not used, because specialized signal-I/O (analysis/re-synthesis) atoms for the filter methods have been implemented. The values of the outputs SR and N are set during the initialization. The output I is initialized to 0 and incremented by 1 after each read cycle. The input REV can be used to reverse the signal in time.